Comprehensive protection device for submersible pump

Abstract

The utility model discloses a comprehensive protection device for a submersible pump. The comprehensive protection device comprises a main control device, a display and a detection circuit, the detection circuit comprises a temperature detection circuit and a water immersion detection circuit; the temperature detection circuit comprises a signal amplification processing circuit, a voltage difference proportion amplification circuit and a sampling channel; the water immersion detection circuit comprises a resistance voltage division circuit, a voltage sampling and impedance matching circuit and a sampling channel; the beneficial effects of the utility model are that the circuit has electrostatic protection capability and peak pulse surge suppression capability, and effectively protects the safety of a post-stage circuit; and the sampling rate, the sampling calculation precision and the stability are improved.

Description

Technical Field

[0001] The utility model relates to the field of submersible pumps, in particular to a comprehensive protection device for submersible pumps. Background Technique

[0002] The existing measurement and protection device for submersible pump motors has a voltage detection circuit for phase voltage and a current detection circuit for phase current; also considering the particularity of the working environment of submersible pump motors, the water seepage detection of its cavity is very important, and a water seepage detection circuit for the cavity is set up.

[0003] However, the current detection circuit design is simple, lacking strong anti-voltage impact ability, lacking the ability to withstand peak pulse surges, unable to effectively protect the safety of the subsequent circuit, and having poor anti-interference ability. Content of the Utility Model

[0004] The utility model provides a comprehensive protection device for submersible pumps to solve one of the problems raised in the above background technique:

[0005] To achieve the above purpose, the utility model provides the following technical solutions:

[0006] A comprehensive protection device for submersible pumps, comprising: a main control device, a display and a detection circuit;

[0007] The detection circuit includes a temperature detection circuit and a water immersion detection circuit;

[0008] The temperature detection circuit includes a signal amplification and processing circuit, a voltage difference proportional amplification circuit, and a sampling channel;

[0009] The water immersion detection circuit includes a resistor voltage division circuit, a voltage sampling and impedance matching circuit, and a sampling channel.

[0010] Further: The main control device includes a microcontroller unit MCU;

[0011] The interface type of the main control device is an RS485 communication circuit, and the RS485 communication circuit uses opto-isolation and has the ability to isolate voltages of at least 5000Vrms; it can be networked and communicated with PLC and PC computers;

[0012] The communication protocol of the main control device is set to Modbus-RTU; it can upload 7 channels of temperature, 3 channels of water immersion resistance values and 3 channels of relay output states for third-party devices or platforms to monitor the operation status of submersible motors in real time;

[0013] The baud rate of the main control device is set to any one of 1200bps, 2400bps, 4800bps and 9600bps.

[0014] Further: The master control device also supports the three-wire PT100 access method and the two-wire PT100 access method.

[0015] Further: The sampling channel is designed as a passive low-pass filter circuit;

[0016] The passive low-pass filter circuit includes: a capacitor;

[0017] a resistor, and the resistor is connected in series with the capacitor;

[0018] The filtering cut-off frequency is less than 20 Hz;

[0019] The sampling channel calculates using the mean filtering algorithm;

[0020] The reference voltage of the sampling channel is 3V;

[0021] It is used to control the filtering cut-off frequency within a range less than 20 Hz, effectively filter out the interference of AC high-frequency signals, and improve the sampling accuracy.

[0022] Further: A TVS transient voltage suppression diode is also placed at the input stage of the sampling channel;

[0023] The TVS tube has excellent voltage clamping ability, fast response time, etc., and realizes electrostatic protection ability beyond level 4 and 600W peak pulse surge suppression ability, effectively protecting the safety of the subsequent circuit.

[0024] Further: The signal amplification and processing circuit includes an unbalanced bridge. The signal amplification and processing circuit includes an unbalanced bridge, and the unbalanced bridge includes: a first adjustable resistor, a first resistor, a second resistor, and a third resistor;

[0025] The first adjustable resistor and the first resistor are connected in series to form a first path;

[0026] The second resistor and the third resistor are connected in series to form a second path;

[0027] The first path is connected in parallel with the second path.

[0028] Further: The resistor voltage division circuit includes a second adjustable resistor and a tenth resistor, and the second adjustable resistor and the tenth resistor are connected in series;

[0029] It is used to convert the resistance change of the water immersion sensor into a voltage signal and send it to the voltage sampling and impedance matching circuit for amplification processing.

[0030] Further: The voltage difference proportional amplification circuit includes a first non-inverting amplifier;

[0031] The non-inverting input terminal and the inverting input terminal of the first non-inverting amplifier are both connected to the signal amplification and processing circuit;

[0032] It is used to proportionally amplify the voltage difference output by the signal amplification processing circuit to meet the sampling accuracy within the sampling range of the MCU.

[0033] Furthermore: The voltage sampling and impedance matching circuit includes a second non-inverting amplifier;

[0034] The non-inverting input terminal of the second non-inverting amplifier is connected to a resistor voltage dividing circuit;

[0035] It is used to impedance-match the voltage output by the resistor voltage dividing circuit with the sampling channel.

[0036] The beneficial effects of the present utility model are as follows:

[0037] 1: It has electrostatic protection ability and peak pulse surge suppression ability, effectively protecting the safety of the subsequent circuit;

[0038] 2: It improves the sampling rate, sampling calculation accuracy and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] For the convenience of those skilled in the art to understand, the present utility model will be further described below in conjunction with the drawings.

[0040] Figure 1 It is a structural schematic diagram of the present utility model;

[0041] Figure 2 It is a structural schematic diagram of the temperature detection circuit of the present utility model;

[0042] Figure 3 It is a structural schematic diagram of the water immersion detection circuit of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] In order to make the purpose, technical solutions and advantages of the present utility model clearer, the present utility model will be further described in detail below in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model, that is, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Usually, the components of the embodiments of the present utility model described and shown in the drawings herein can be arranged and designed in various different configurations.

[0044] Therefore, the detailed description of the embodiments of the present utility model provided in the drawings below is not intended to limit the scope of the present utility model to be protected, but only represents the selected embodiments of the present utility model. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present utility model.

[0045] The present utility model is only limited by the claims and their full scope and equivalents. In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present utility model, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0046] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and defined, the terms "installed", "connected", "coupled", etc. shall be construed in a broad sense. For example, it may be an installation connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model may be understood according to specific circumstances.

[0047] To better understand the solutions of the embodiments of the present application, some related terms and concepts that may be involved in the embodiments of the present application will be introduced below.

[0048] Modbus-RTU: Modbus is an application layer protocol that defines data units (ADUs) independent of the underlying network and can communicate over Ethernet (TCP / IP) or serial links (RS232, RS485, etc.) (the Ethernet ADU and the serial ADU are slightly different). On serial links, the Modbus protocol has two transmission modes - ASCII mode and RTU mode. Among them, ASCII is the abbreviation of the English phrase "American Standard Code for Information Interchange", which is translated into Chinese as "American National Standard Code for Information Interchange"; RTU is the abbreviation of the English phrase "Remote Terminal Unit", which is translated into Chinese as "Remote Terminal Device". When the controller is set to communicate in RTU mode on the Modbus network, each 8-bit byte in the message contains two 4-bit hexadecimal characters, and this mode has no start and end markers. Its advantage is that more data can be transmitted at the same baud rate. In RTU (Remote Terminal Unit) mode, each byte can transmit two hexadecimal characters. For example, for the hexadecimal number 0xAF, it is directly sent as hexadecimal 0xAF (binary: 10101111), so its transmission density is twice that of the ASCII mode; the RTU mode uses cyclic redundancy check (CRC).

[0049] Please refer to Figure 1, in the embodiment of the present utility model, a comprehensive protection device for a submersible pump includes a main control device, a display, and a detection circuit; the detection circuit includes a temperature detection circuit and a water immersion detection circuit; the temperature detection circuit includes a signal amplification and processing circuit, a voltage difference proportional amplification circuit, and a sampling channel; the water immersion detection circuit includes a resistance voltage division circuit, a voltage sampling and impedance matching circuit, and a sampling channel.

[0050] Specifically: the main control device includes a microcontroller unit MCU; the interface type of the main control device is an RS485 communication circuit, and the RS485 communication circuit uses opto-isolation and has an isolation voltage capacity of at least 5000Vrms, and can be networked and communicated with a PLC or a PC computer; the communication protocol of the main control device is set to Modbus-RTU, and it can upload 7 channels of temperature, 3 channels of water immersion resistance values, and 3 channels of relay output states for real-time monitoring of the operation status of the submersible motor by third-party devices or platforms; the baud rate of the main control device is set to any one of 1200bps, 2400bps, 4800bps, and 9600bps; the main control device also supports the three-wire PT100 access method and the two-wire PT100 access method.

[0051] Please refer to Figure 2 , the structural schematic diagram of the temperature detection circuit of the present utility model;

[0052] Among them, the part in the red frame is the signal amplification and processing circuit, including an unbalanced bridge, and the unbalanced bridge includes: a first adjustable resistor R9, a first resistor R1, a second resistor R2, and a third resistor R3; the first adjustable resistor R9 and the first resistor R1 are connected in series to form a first path; the second resistor R2 and the third resistor R3 are connected in series to form a second path; the first path and the second path are connected in parallel; the unbalanced bridge part is mainly responsible for converting the resistance change of the temperature sensor (i.e., the first adjustable resistor R9) into an unbalanced voltage and sending it to the voltage difference proportional amplification circuit;

[0053] The part in the green frame is the voltage difference proportional amplification circuit part, including a first non-inverting amplifier U1A; the non-inverting input terminal and the inverting input terminal of the first non-inverting amplifier U1A are both connected to the signal amplification and processing circuit; it is responsible for proportionally amplifying the voltage difference output by the previous stage to meet the sampling accuracy within the sampling range of the MCU;

[0054] The part in the black frame is the sampling channel; the sampling channel is designed as a passive low-pass filter circuit; the passive low-pass filter circuit includes: a capacitor; a resistor, and the resistor is connected in series with the capacitor; a TVS transient voltage suppression diode is also placed at the input stage of the sampling channel; the filter cut-off frequency is less than 20Hz; the sampling channel calculates using the mean filtering algorithm; the reference voltage of the sampling channel is 3V; it is responsible for filtering out the AC noise introduced by the previous stage and improving the overall sampling accuracy.

[0055] Please refer to Figure 3, Schematic diagram of the water immersion detection circuit structure of the present utility model;

[0056] Among them, the part within the red frame is the resistor voltage division circuit, including the second adjustable resistor R11 and the tenth resistor R10, and the second adjustable resistor R11 and the tenth resistor R10 are connected in series; it is responsible for converting the resistance change of the water immersion sensor (i.e., the second adjustable resistor R11) into a voltage signal and sending it to the subsequent operational amplifier for signal amplification processing;

[0057] The part within the green frame is the voltage sampling and impedance matching circuit, including the second non-inverting amplifier U1B; the non-inverting input terminal of the second non-inverting amplifier U1B is connected to the resistor voltage division circuit; it is responsible for impedance matching between the voltage output by the previous stage and the sampling of the subsequent stage;

[0058] The part within the black frame is the sampling channel, which is Figure 2 the same as the sampling channel of the temperature detection circuit structure.

[0059] The working principle of the present utility model is specifically as follows: The main control device adjusts the detection range, and the temperature detection circuit and the water immersion detection circuit constantly detect whether the temperature and water ingress exceed the set range values. The detected results are directly sent to the main control device for judgment of whether to alarm, and then sent by the main control device to the display for display.

[0060] The above content is only an example and explanation of the structure of the present utility model. Those skilled in the art of this technology make various modifications or supplements or use similar methods to replace the specific embodiments described. As long as they do not deviate from the structure of the utility model or exceed the scope defined by this claim book, they should all fall within the protection scope of the present utility model.

Claims

1. An integrated protection device for a submersible pump, characterized in that, Including: A main control device, a display, and a detection circuit; The detection circuit includes a temperature detection circuit and a water immersion detection circuit; The temperature detection circuit includes a signal amplification and processing circuit, a voltage difference proportional amplification circuit, and a sampling channel; The water immersion detection circuit includes a resistor voltage division circuit, a voltage sampling and impedance matching circuit, and a sampling channel.

2. The integrated protection device for a submersible pump according to claim 1, characterized in that, The main control device includes a microcontroller unit MCU; The interface type of the main control device is an RS485 communication circuit, and the RS485 communication circuit uses opto-isolation and has an isolation voltage capacity of at least 5000Vrms; The communication protocol of the main control device is set to Modbus-RTU; The baud rate of the main control device is set to any one of 1200bps, 2400bps, 4800bps, and 9600bps.

3. The integrated protection device for a submersible pump according to claim 1, characterized in that, The main control device also supports the three-wire PT100 access method and the two-wire PT100 access method.

4. An integrated protection device for a submersible pump according to claim 1, characterized in that, The sampling channel is designed as a passive low-pass filter circuit; The passive low-pass filter circuit includes a capacitor and a resistor, and the resistor is in series with the capacitor.

5. The integrated protection device for a submersible pump according to claim 4, characterized in that, A TVS transient voltage suppression diode is also placed at the input stage of the sampling channel.

6. The integrated protection device for a submersible pump according to claim 1, wherein, The signal amplification and processing circuit includes an unbalanced bridge, and the unbalanced bridge includes a first adjustable resistor, a first resistor, a second resistor, and a third resistor; The first adjustable resistor and the first resistor are in series to form a first path; The second resistor and the third resistor are in series to form a second path; The first path is in parallel with the second path.

7. The integrated protection device for a submersible pump according to claim 1, characterized in that, The resistor voltage division circuit includes a second adjustable resistor and a tenth resistor, and the second adjustable resistor and the tenth resistor are in series.

8. The integrated protection device for a submersible pump according to claim 1, characterized in that The voltage difference proportional amplification circuit includes a first non-inverting amplifier; The non-inverting input terminal and the inverting input terminal of the first non-inverting amplifier are both connected to the signal amplification and processing circuit.

9. The integrated protection device for a submersible pump according to claim 1, characterized in that, The voltage sampling and impedance matching circuit includes a second non-inverting amplifier; The non-inverting input terminal of the non-inverting amplifier is connected to the resistor voltage division circuit.

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